Re: [PATCH V2 4/4] intel-iommu: PASID support

[Jason Wang]

On Fri, Apr 1, 2022 at 9:43 PM Yi Liu <yi.l.liu@intel.com> wrote:
>
>
>
> On 2022/3/29 12:54, Jason Wang wrote:
> >
> > 在 2022/3/28 下午4:45, Yi Liu 写道:
> >>
> >>
> >> On 2022/3/21 13:54, Jason Wang wrote:
> >>> This patch introduce ECAP_PASID via "x-pasid-mode". Based on the
> >>> existing support for scalable mode, we need to implement the following
> >>> missing parts:
> >>>
> >>> 1) tag VTDAddressSpace with PASID and support IOMMU/DMA translation
> >>>     with PASID
> >>
> >> should it be tagging with bdf+pasid?
> >
> >
> > The problem is BDF is programmable by the guest. So we may end up
> > duplicated BDFs. That's why the code uses struct PCIBus.
>
> how about the devfn? will it also change?

The code has already used devfn, doesn't it?

struct vtd_as_key {
    PCIBus *bus;
    uint8_t devfn;
    uint32_t pasid;
};

Thanks

>  taggiing addressspace with
> BDF+PASID mostly suits the spec since the PASID table is per-bdf. If
> bus number may change, using PCIBus is fine.
>
> Regards,
> Yi Liu
>